Changes in the composition of volatile monoterpenes and sesquiterpenes of Pinus armandi, P-tabulaeformis, and P-bungeana in Northwest China

The volatile mono- and sesquiterpenes obtained from the needles and resin of Pinus armandi, P. tabulaeformis, andP. bungeana growing in the Qinling, Taibai, and Huanglong Mountain forest ecosystem were analyzed by means of GC-MS. Forty-eight constituents were identified, and alpha-pinene, beta-pinene, IR-alpha-pinene, beta-caryophyllene, cadindiene, alpha-caryophyllene, D-limonene, and IS-beta-pinene were the major components of the mono- and sesquiterpenes in the needles and resin. The components of the volatile mono- and sesquiterpenes from the needles and resin at Qinling, Taibai, and Huanglong Mountains had remarkable differences in three pine specifies, whereas the monopertene content such as alpha-pinene, beta-pinene, D-limonene, and camphene were mostly changed in the growing stage. The intraspecies variation in the different ecosystems can be attributed to the species' geography and genetic variation, and even the adaptation of the pine species to different ecological environments. Moreover, monoterpenes and sesquiterpenes can be induced by the attack of bark beetles, of which the alpha-pinene, beta-pinene, IR-alpha-pinene, IS-alpha-pinene, beta-myrecene, and beta-caryophyllene contents had positive relations with the attacking Dendroctonus armandi and D. valens.